OFFSET
3,2
COMMENTS
a(n) is also the number of distinct possible (n-1)-dimensional simplices if the (n-1)*n/2 1-faces are given (up to symmetry, rotation, reflection). - Dan Dima, Nov 03 2011
a(n) is also the number of edge labelings of the complete graph on n vertices. - Nikos Apostolakis, Jul 09 2013
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Alois P. Heinz, Table of n, a(n) for n = 3..30
O. Frank and K. Svensson, On probability distributions of single-linkage dendrograms, Journal of Statistical Computation and Simulation, 12 (1981), 121-131. (Annotated scanned copy)
C. L. Mallows, Note to N. J. A. Sloane circa 1979.
EXAMPLE
a(3)=1 since there is one possible triangle if the 3 edges are given and a(4)=30 since there are 30 distinct possible tetrahedra if the 6 edges are given. - Dan Dima, Nov 03 2011
MATHEMATICA
Table[Binomial[n, 2]!/n!, {n, 3, 20}] (* Harvey P. Dale, May 08 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved